I have been trying to find the perfect ferret collar for about 4 years now
and have finally figured it out.  I make my own collars now out of leather
shoelace, a split-ring for the bell, and a bell from Petsmart.  The collars
are wonderful and the ferrets aren't able to get them off easily.  Just make
sure that you can put a finger between the collar and their neck and your
guys will be fine.  Try to make one...you'll find that it stays on sooo much
longer than those cat collars.
 
Melanie and the gang (Maggie, Gizma, and Norman)
[Posted in FML issue 1883]